• International Journal of Aeronautical and Space Sciences
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• v.11 no.1
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• pp.1-9
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• 2010

Numerical simulation of unsteady flows around helicopters was conducted to investigate the aerodynamic interaction of main rotor and other components such as fuselage and tail rotor. For this purpose, a three-dimensional inviscid flow solver has been developed based on unstructured meshes. An overset mesh technique was used to describe the relative motion between the main rotor, and other components. As the application of the present method, calculations were made for the rotor-fuselage aerodynamic interaction of the ROBIN (ROtor Body INteraction) configuration and for a complete UH-60 helicopter configuration consisted of main rotor, fuselage, and tail rotor. Comparison of the computational results was made with measured time-averaged and instantaneous fuselage surface pressure distributions for the ROBIN configuration and thrust distribution and available experimental data for the UH-60 configuration. It is demonstrated that the present method is efficient and robust for the simulation of complete rotorcraft configurations.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.213-220
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• 2014

A program that predicts trajectories of projectiles influenced by the interference flow field of helicopters is developed. The interference flow field are computed using a compressible inviscid solver in conjunction with an actuator disc model. The trajectories are predicted using 6-DOF (Degree of Freedom) equations as well as an alternative form of modified point mass equations of motion. The method for the interference flow field prediction method are validated with ROBIN(ROtor Body INteraction) model. A Sierra international bullet and a 105mm projectile are used to validate the trajectory method. Trajectories of a Sierra International bullet and a HYDRA 70 rocket firing from a helicopter are predicted.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.7
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• pp.629-636
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• 2010

This study is to investigate the aerodynamic effects of the Rotor-Fuselage Interactions in forward flight, and is conducted by using an improved time-marching free-wake panel method. To resolve the instability caused by the close proximity of the wake to the blade surface, the field velocity approach is added to the prior unsteady panel code. This modified method is applied to the ROBIN(ROtor Body Interaction) problem, which had been conducted experimentally in NASA. The calculated results, pressure distribution on fuselage surface and induced inflow ratio without and with the rotor, are compared with the experimental results. The developed code shows not only very accurate prediction of the aerodynamic characteristics for the rotor-fuselage interaction problem but also the rotor wake development.